Cooling means for air hammer dies



June 2 5. 1946.

G; C. WHITMAN COOLING MEANS FOR AIR HAMMER DIES Filed June 2, 1943 R m M mm 5 C m v 4 0 Patented June 25, 1946 UNITED STATES PATENT OFFICE COOLING MEANS FOR AIR HAMMER DIES Grover C. Whitman, Berkeley, Calif.

Application June 2, 1943, Serial No. 489,371

1 Claim.

This invention relates to air hammers and particularly pertains to a means of cooling the same.

It is the principal object of my present invention to improve air hammers of the type utilizing a flush die by providing the same withan improved means of maintaining the die cool, thus eliminating breakage of the die due to overheating and enabling it to be grasped by the hand of the riveter using the gun without discomfort.

Other objects and advantages will be apparent from the accompanying description and drawing.

In practicing my invention the die end of the gun is fitted with a pliable sleeve or shield which circumscribes the die and the adjacent end of the gun barrel. This sleeve is preferably but not necessarily formed of heavy pliable leather and is of an interior diameter very loosely fitting the die and barrel. An air delivery conduit is provided along the exterior of the barrel and is connected at one end to the source of air supply to the gun. At its other end the conduit terminates in a nozzle interposed between the sleeve and the barrel so that the air will discharge axially between the sleeve and the die. Thus, cooling air under pressure will constantly pass between the exterior of the die and the sleeve, causing a sufficient exchange of heat to prevent the die from overheating and enabling it to be maintained cool enough to be held by the riveter grasping it through the shield.

One form which the invention may assume is exemplified in the following description and illustrated by way of example in the accompanying drawing, in which the figure is a view in side elevation of an air hammer embodying the preferred form of my invention.

Referring more particularly to the accompanying drawing, I indicates an air gun of a standard type used in riveting. This gun has the usual barrel ll, hand grip l2, and die 14. The latter is what is commonly termed a flush die and is slightly tapered as shown. The die head l4 ordinarily projects approximately 3 inches from the adjacent end of the barrel [I so that it may be grasped by the hand of the riveter.

It is well known that dies of this type rapidly heat and become so hot that its temper is withdrawn and breakage thereof results. comes so hot that it cannot be handled by the riveter. To eliminate these disadvantages I have provided a means of cooling the die I l. The means referred to includes a sleeve or shield I5 preferably formed of heavy pliable leather which is shaped to conform to the contour of the die and barrel as illustrated. The interior diameter of the shield [5, however, is somewhat larger than the external diameter of the die I4 and barrel H so that an annular air passage It will be Also it ber formed therebetween as shown. This shield or sleeve, of course, permits the die to be firmly grasped in the hand of the riveter due to its pliability.

I intend that air under pressure be constantly supplied to the annular passage I 6 and so directed that it will discharge through the same at the die end of the shield. This cooling air will effect an exchange of heat with the die l4 and the end of the barrel H and maintain the same at a temperature preventing crystallization and breakage of the die. Likewise it will maintain it sufficiently cool that the die may be grasped by the riveter through the shield.

To supply the cooling air, I have fitted the exterior of the barrel II with a conduit [1 connected at one end with the air supply conduit or line I8 to the gun Ill. The other end f the conduit is interposed between the shield l5 and the barrel and is forwardly directed. A control valve i9 is provided for controlling the discharge of air through the conduit [1. Obviously when the valve I9 is open, air under pressure discharges into the annular space 16 and forwardly over the die through the forward end of the shield, thus air cooling the die.

In actual practice I have found that this cooling is suflicient not only to prevent overheating of the die and consequently the breaking thereof, but enables it to be gripped by the riveter through the shield. Such gripping is necessary of course, because without it the gun cannot be operated in driving rivets.

I have also found that the discharge of the air in the manner stated, blows slag from the rivet hole and keeps the surrounding area of the plate clean.

From the foregoing it is obvious that I have provided a simple but very effective medium of cooling dies in air hammers.

While I have shown the preferred form of my invention, it is to be understood that various changes may be made therein by those skilled in the art without departing from the spirit of the invention as defined in the appended claim.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

In combination with an air hammer having a flush die projecting from the end of the-barrel thereof, an open ended pliable leather shield arranged over the die and the adjacent end of the gun barrel, a conduit arranged along the gun barrel and having an open end projected between the same and the shield to direct a stream of air under pressure forwardly and between and over and around the die, the other end of the conduit being connected with the source of air supply to the air hammer, and a valve in said conduit.

GROVER C. WHITMAN. 

